Answer:
56
Step-by-step explanation:
Complete question:
Z varies jointly with x and y , x=2 and y=2, z=7. Find z when x=4 and y=8 using joint variation . (I need the problem worked out step by step)
If z varies jointly with x, and y, this is expressed as;
z = kxy
If z=7 when x= 2, y= 2
7 = k(2)(2)
7 = 4k
k = 7/4
To get z when x= 4 and y = 8
z = kxy
z =7/4 (4)(8)
z = 7*8
z = 56
Hence the value of z is 56
Answer:
Decay
Step-by-step explanation:
We are given an equation 
We need to say about decay or growth of exponential function.
Exponential function: 
Where,
- a is initial value of exponential function.
- b is decay or growth of function
For decay: 0<b<1
For growth: b>1
Now we rewrite the equation into this form

Changes to

Here, b=0.5 < 1
Therefore, The given function would be decay.
Thus,
is deacy.
To find the cost of 1 pound, we need to divide $19.14 by 3.25 pounds. 19.14/3.25= 5.88923076923. We can round this to the nearest hundredths to make $5.89. So, the cost of 1 pound of coffee beans is $5.89. Hope this helped!